Usually at my “Storytelling with Business Data” workshops audience splits into pie-chart-lovers (hopefully minority) and pie-chart-haters (hopefully majority). But it is hard to find a single person in the audience, who has never created a pie chart.
Pie chart is probably one of the most overused charts in data visualization history.
And they indeed have one strong side – they clearly show that parts form the whole, i.e. add up to 100%
But we pay quite high price for that.
Pie charts are difficult to read. Our eye works in a way, that it is hard for us to compare size of different segments, it requires comparing angle width and arc length.
In the best case we can tell which segment is bigger (not always the case), but we struggle with telling by how much.
It is easier for us to compare just one simple parameter, like length of a line… or a bar.
That is why many experts recommend replacing pie chart with a bar chart.
See for yourself: